盐碱地排水沟蓄水后底泥与水体盐分交换试验

因长期累积效果,盐碱地排水沟内盐分含量不断升高,危及排水沟系统的生态功能,利用淡水定期进行稀释可延缓盐分累积过程.该文以陕西富平县卤泊滩盐碱地改良区为例,通过实验室土柱试验,研究了排水沟蓄集淡水、水体保持静态条件下,底泥与上覆水体的盐分交换规律,揭示了底泥盐分释放的内在机理.研究结果表明,在分子扩散作用下底泥-上覆水界面之上10 cm 的范围内存在一个高盐分渐变区（即扩散边界层）,10 cm 以上的水体盐分基本一致;分子扩散是边界层内盐分运移的主要机制;扩散边界层对底泥盐分释放具有一定的阻滞作用,并且随着边界层厚度的增加,阻滞效应也显著增强;底泥盐分释放通量符合负的幂指数形式....

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Bibliographic Details
Published in农业工程学报 Vol. 29; no. 2; pp. 81 - 87
Main Author 潘延鑫 罗纨 贾忠华 李进 陈远
Format Journal Article
LanguageChinese
Published 西安理工大学教育部西北水资源与环境生态重点实验室,西安 710048 2013
Subjects
底泥
扩散边界层
排水
水质
盐分
盐碱地
ditch sediment
扩散边界层
盐碱地
water quality
saline farmland
盐分
水质
drainage
底泥
排水
diffusive boundary layer
salts
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ISSN1002-6819
DOI10.3969/j.issn.1002-6819.2013.02.012

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Summary:因长期累积效果,盐碱地排水沟内盐分含量不断升高,危及排水沟系统的生态功能,利用淡水定期进行稀释可延缓盐分累积过程.该文以陕西富平县卤泊滩盐碱地改良区为例,通过实验室土柱试验,研究了排水沟蓄集淡水、水体保持静态条件下,底泥与上覆水体的盐分交换规律,揭示了底泥盐分释放的内在机理.研究结果表明,在分子扩散作用下底泥-上覆水界面之上10 cm 的范围内存在一个高盐分渐变区（即扩散边界层）,10 cm 以上的水体盐分基本一致;分子扩散是边界层内盐分运移的主要机制;扩散边界层对底泥盐分释放具有一定的阻滞作用,并且随着边界层厚度的增加,阻滞效应也显著增强;底泥盐分释放通量符合负的幂指数形式.
Bibliography:Pan Yanxin, Luo Wan, Jia Zhonghua, Li Jin, Chen Yuan （1. Northwest Key Laboratory of Water Resource and Enviroment Ecology, Minstry of Education, Xi ＇an University of Technology, Xi ＇an 710048, China）
11-2047/S
In arid and semi-arid agricultural regions, artificial drainage is provided to maintain salt balance of the saline farmland. As a result of poor drainage outlet in some sites, salt accumulation in the drainage ditches often leads to salinity rising to a critical level that threatens ecological functions of the ditch system. Periodic flushing with fresh water has been suggested to slow down the process of salinity growth in such ditch system. But the effect of the slow moving freshwater in drainage ditches on salt balance is unclear. In order to investigate the internal mechanism of salt release in saline drainage ditches when freshwater is added, and to examine the relationship of salt exchange between sediment and the overlying water under hydrostatic condition, we conducted a laboratory study to measur
ISSN:1002-6819
DOI:10.3969/j.issn.1002-6819.2013.02.012